Beverage brewing method with variable speed dispense pump

ABSTRACT

A method of brewing hot beverage with an electric hot beverage brewer (20) with a duty cycle modulated DC voltage dispense pump (44) with an inlet (46) connected to a de-aerator (24) and beneath a lower limit and an outlet (48) located above an upper limit the surface a hot water tank (22) is finely controlled by a high frequency pulse-width, modulated, square power input voltage (FIG. 2) with a duty cycle controlled in accordance with predetermined profiles stored within a controller (28) to selectively change the flow rate out of the pump onto a distribution dome (50) during a dispense period of a brew cycle to achieve optimum brewing of different types of beverage ingredients and varieties of the different types and to selectively change the spray pattern of hot water onto the ingredient (53) within the basket assembly (52) between vertical and acute angles including acute angles that pass hot water into a bypass gap (56).

CROSS-REFERENCE TO RELATED APPLICATIONS

This application a divisional application and claims the benefit under35 U.S.C. 120 of its parent application, U.S. patent application Ser.No. 13/706,561, filed Dec. 6, 2012 for “Beverage Brewer with DispensePump and Method, hereby incorporated herein by reference, which, inturn, claims the benefit under 35 U.S.C. 119(e) of provisional patentapplication 61/567,793, filed Dec. 7, 2011, and entitled “BeverageBrewer with Dispense Pump and Method”, which is also hereby incorporatedby reference.

BACKGROUND Field of the Invention

This invention generally relates to electrical hot beverage brewers andmore particularly to electrical, drip-type, hot beverage brewers thatoperate automatically to pass hot water into a brew basket containingbeverage ingredient to be mixed with the hot water to make the beverage.

Discussion of the Prior Art

Electrical hot beverage brewers, such as coffee brewers or tea brewers,of the type that operate automatically to pass a preselected amount ofhot water into a brew basket are well known. The brew basket containsdry beverage ingredient, such as ground coffee or tea leaves, whichpartially dissolves into the hot water to make the freshly brewedbeverage.

Commercial drip-type beverage brewers of this type produce between onehalf gallon to three gallons per brew cycle by distributing hot waternear boiling temperature (e.g. 195-203 degrees Fahrenheit), or brewwater, on ground coffee or tea leaves supported on a coffee filterwhich, in turn, is supported by a mesh or otherwise porous filter holderinside a water impervious brew basket body. The brewing water extractsthe desired principle from the ingredient to produce the filteredbeverage that passes out of a drain hole at the bottom of the brewbasket body and into a suitable container, such as an insulateddispenser. Optimal brew time is generally between three and six minutesdepending upon whether coffee or tea is being made and further dependingupon the different types and varietals of each.

There are several different dispense flow rate control methods. The mostbasic commercial brewer is a pour over type where water is poured intothe brewer and displaces or flows through a hot water tank to be heatedand distributed into the brew basket. An orifice plate or other passivemechanical device controls the flow rate through the hot water tank tothe spray head. The orifice size is based on the heating rate of the hotwater tank and the desired rate of flow over the beverage ingredient.

In another method, a hot water tank is filled by adding in fresh coldwater at the bottom of the tank to displace the hot water that isdischarged into the brew basket. The inlet water is passed through asolenoid-controlled inlet fill valve which is opened and kept open for apreselected electronically timed dispense period needed to deliver thedesired quantity of brew water. As the cold water enters the tank at thebottom, the hot brew water at the top of the tank flows out of the verytop of the hot water tank (where the water is the hottest) through aflow control device and distributed into the brew basket by a suitablespray distribution head.

In a third method, two different solenoid-controlled valves areemployed. An inlet fill valve fills the tank to a preselected level andmaintains the level in response to upper and lower level sensors of thehot water tank, and another solenoid-controlled valve, or dispensevalve, releases water from the top of the tank through a spraydistribution head to the brew basket. The dispense valve most often usedis a solenoid-controlled dump valve of a fixed size. However, otherelectromechanically controlled means may be employed in lieu of thesingle dispense valve, examples of which are shown in U.S. Pat. No.5,331,885 issued to Zbigniew G. Lassota on Jul. 26, 1994 for aninvention entitled “Semiautomatic Beverage Maker and Method and U.S.Pat. No. 5,000,082 issued to Zbigniew G. Lassota on Mar. 19, 1991 for aninvention entitled “Beverage Maker and Method of Making a Beverage”,both of which are hereby incorporated by reference. There are threeknown methods of distributing the brew water into the brew basket whichrespectively employ a flow disc regulator with spray cutters, aperforated plate and a cascading spray dome. All three methods directthe flow of the brewing water into the brew basket and assist in controland regulation of the flow rate.

The flow disc regulator and spray cutters work together and are matchedfor the type, quantity and quality of coffee or tea being brewed and thebatch size.

The perforated plate, which resembles a shower head or salt shaker top,directs the brewing water into the brew basket in a uniform shower orspray pattern.

A cascading spray dome directs the optimal pattern for a given flow bydirecting brew water over the outside of an umbrella shaped dome.Upwardly facing channels on the surface of the dome that radially extendto the peripheral edge of the dome direct individual streams of thewater into the brew basket. Reference should be made to U.S. Pat. No.7,866,255 issued to Leszak M. Wroblewski and Zbigniew G. Lassota on.Jan. 11, 2011 for an invention entitled “Beverage Brewer with SprayDistribution Assembly and Method”, which is hereby incorporated byreference.

It is extremely important for commercial food service beverage,catering, and office coffee service (OCS) brewers to produce a reliablebrewed beverage with the desired 3-6 minutes that is consistent inflavor, taste and texture from one brew cycle to the next.Unfortunately, all of the known methods of brewing suffer from the samefour liabilities: (1) complexity of design that is difficult andexpensive to operate and service, (2) difficulty in varying the brewdispense time periods to accommodate the needs for different types andvarieties of beverage ingredient, (3) a need for the presence of a largenumber of needed components and support systems, and (4) lack of finecontrol over the spray and flow patterns and flow rates.

Accordingly, there is a need for a new apparatus and method thatprovides automatic fine and repeatable control of both flow rates andspray distribution patterns in an electric, automatic, drip-type brewer.

SUMMARY OF THE INVENTION

The inventors have determined that even for different brew cycles of thesame batch size, it may be desirable to have a high flow rate for somebeverage ingredients and a lower flow rate for other beverageingredients. A finished beverage can have entirely different taste andextracted content characteristics based on the type of exposure to theflow rate and timing of the brew water distributed to the brew basket.It is therefore a general object of the present invention to provide aof brewing for use in an electrical brewer a method in which theinstantaneous non-zero flow rate during the course of a brew cycle andthe brew time may be controlled independently.

The inventors have also determined that another important factor thatmust be controlled for optimum brewing is the spray pattern of thebrewing water impacting on the beverage ingredient within the brewbasket. Some brewing ingredients require a forceful spray to createturbulence while others brew best with a steady or intermittent shower.The spray may need to be balanced between the outer area near the sidewall of the filter paper upon which the ingredient is supported and thecenter of the brew basket. Brew water spray can be forceful with areduced flow for a longer duration than a forceful high-volume spray fora short time. Thus, it has been ascertained that both the flow rate andpattern of the brewing water distribution into the brew basket directlyaffects quality of the finished beverage.

It is therefore also a general object of the invention to provide abrewing method for use in a commercial hot beverage brewer in which itis possible to tightly control the flow rate in order to achieveconsistent final results from one brewing cycle to the next for the samebrewing ingredient. The flow rate and spray pattern may be selectablyvaried to accommodate for both differences in the type of ingredient(e.g. coffee, tea, etc.) and as well as varieties of the same type ofingredient (e.g. decaffeinated coffee, specialty roast varietals ofcoffee, etc.) of the beverage being brewed.

It is also therefore an object of the present invention to provide amethod of brewing for use in a beverage brewer that achieves the abovequalities but also overcomes the aforementioned problems anddisadvantages of known brewers and brewing methods.

These objectives are achieved, in part, by provision for use in anelectrical beverage brewer with a brew basket for holding beverageingredient for brewing a beverage, an unpressurized hot water tank, awater fill system for maintaining water level in the tank betweenpreselected limits, a method of brewing by performance of the steps of,dispensing hot water from the hot water tank with a variable speed pumponto a spray distribution dome with an upper surface for receiving hotwater from the pump, said dome having upwardly facing, open, surfacechannels to direct the hot water from the pump into individual streamsof hot water deposited into the brew basket, and controlling with anelectronic controller a variable electrical power supply connected tothe pump to selectively change the application of electrical power tothe variable speed pump to selectively vary the flow rate of hot waterpassing out of the pump and onto the spray distribution dome during apreselected dispense period of a brew cycle, and creating with saidspray distribution dome substantially different spray patterns inresponse to receiving hot water at different preselected flow rates ofthe pump.

Preferably, the brewing method includes the steps of producing avariable DC power voltage with the variable electrical power supplyhaving a square wave configuration with a duty cycle that is selectivelyvaried to selectively change the average DC power being produced by thevariable electrical power supply, storing a program in the controllerwith a dispense profile that includes at least one period during which afirst duty cycle is selected for a relatively low pump flow rate tocause the streams of water to flow downward from the dome into the brewbasket in a relatively vertical direction, and at least one other periodduring which a second duty cycle greater than the first duty cycle isselected for a relatively high flow rate to cause the streams of waterto flow downwardly and outwardly from the dome at an acute anglerelative to vertical.

Yet, another object is achieved in a preferred embodiment of the brewingmethod in which the brew basket has an outer water impervious protectivebody with an outer top edge and an inner water pervious filter holderwith an upper perimeter spaced from the outer top edge to provide a gapfor the passage of bypass water, and including the step of operating thepump at a flow rate sufficiently high to cause at least some of thestreams of water to flow downwardly and outwardly from the dome at anacute angle and pass through the bypass water gap and miss the filterholder.

The brewing method of preferably includes the steps of storing in amemory of a controller a plurality of brew dispense profiles stored inmemory, and including the step producing the variable electrical powersupply a variable DC power voltage with a square wave DC output voltagehaving a duty cycle that is selectively varied in accordance with theprofiles to selectively change the average DC power being provided tothe variable speed pump during a dispense period.

The objects of the invention are also achieved in part by provision foruse in an electrical beverage brewer, a method of brewing, by performingthe method steps of maintaining water level in a hot water tank betweenpreselected limits located sufficiently close together to maintain asubstantially uniform head pressure in the hot water tank;

holding ingredient to be brewed upon mixing with hot water in a brewbasket, dispensing water into the brew basket with a water dispensesystem by pumping hot water out of the hot water tank with a variablespeed electrical pump, and selectively varying with a power controllingmeans an amount of non-zero electrical power to the pump to selectivelyvary a non-zero speed of the pump and resultant flow rate of hot waterout of the pump, said power controlling selectively changing a DC powervoltage greater than zero provided to the pump to selectively vary anon-zero speed of the pump and resultant non-zero flow rate duringoperation of the pump.

Preferably, the brewing method of claim 6 including the steps ofdirecting hot water from the pump, with a dome shaped configuration aspray distribution head, into individual streams of hot water that enterthe brew basket in a vertical direction and selectively varyingnon-vertical directions depending upon flow rate of the pump.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing objects features and advantages of the invention will bedescribed and otherwise will be made apparent from the detaileddescription below that is given with reference to the several figures ofthe drawings, in which:

FIG. 1 is a functional block diagram of e beverage brewer of the presentinvention;

FIG. 2 is an exemplary schematic chart of the changing flow rate overtime during intermittent, or pulse brew, operation in which thecontrolled flow rate is gradually increased and decreased at thebeginnings and ends of each of the pulses of flow;

FIG. 3 is an exemplary schematic chart of the varying duty cycle of theDC voltage provided to the pump that gradually increases during gradualincreases of the average DC voltage provided to the pump and thecorresponding resultant gradually increased flow rate, as illustrated inFIG. 6 .

FIG. 4 is an exploded sectional view of the preferred spray head for usewith the beverage brewer of FIG. 3 ;

FIG. 5A is a schematic illustration of a relatively narrow and verticalspray pattern generated by the spray distribution assembly when thedispense pump is operated at a relatively lower DC voltage andcorresponding relatively lower flow rate;

FIG. 5B is a schematic illustration of the relatively narrow andvertical spray pattern of FIG. 5A in reference to the brew basket andfilter holder within the brew basket;

FIG. 6A is a schematic illustration of a relatively broad and spraypattern generated by the spray distribution assembly when the dispensepump is operated at a relatively higher DC voltage and correspondingrelative higher flow rate;

FIG. 68 is a schematic illustration of the relatively broad spraypattern of FIG. 6A in reference to the brew basket and filter holderwithin the brew basket;

FIG. 7 is a sectional side view of the brew basket of FIG. 1illustrating the presence of peripheral bypass gaps to allow water topass by the brew basket and directly into the dispenser of FIG. 1 ;

FIG. 8A is a schematic illustration of a relatively broadest spraypattern generated by the spray distribution assembly of FIG. 4 when thedispense pump is operated at a relatively highest DC power voltage andat a corresponding highest flow rate such that some of the spray passesthrough the bypass gap of FIG. 7 ;

FIG. 8B is a schematic illustration of the relatively broadest spraypattern of FIG. 8A in reference to the brew basket and bypass gap ofFIG. 7 ;

FIG. 9 is a detailed perspective exploded illustration of one embodimentof the tank and its connections with the pump and spray distributionhead and also including an optional second pump, or bypass pump,provided solely for pumping a selected amount of bypass water into abypass gap between the outer body of the brew basket and the filter andingredient holder;

FIG. 10 is another perspective view of a portion of the tank, pump andspray distribution head of FIG. 9 but with the pump and spraydistribution head in an interconnected state; and

FIG. 11 is another perspective isolated view similar to that of FIG. 10but enlarged to better illustrate the connection tubing between the pumpand the motor and between the pump and spray distribution head.

DETAILED DESCRIPTION

Referring to FIG. 1 , a preferred embodiment of the hot beverage brewer20 of the present invention has a hot water tank 22 with a capacity ofapproximately 2.5-3.0 or 4.5-5.0 gallons depending upon whether thebrewer is a single brewer or a twin brewer, respectively. Thesequantities within the hot water tank are needed in order to make atypical one gallon or three-liter batch during a single brew cycle.Batch size is preferably one gallon but may be one-half to two gallonsin half gallon increments.

The hot water tank 22 includes a unique de-aerator 24 mounted to oneside of the tank 22 and adjacent to a hollow, tubular fitting 26 toprovide open fluid communication between the interior of the tank 22 andthe exterior, that will be explained in greater detail below.

A microprocessor controller, or controller, 28 receives input signalsfrom an upper level sensor 30 and a lower level sensor 32 to control asolenoid-controlled tank fill valve 34 to selectively open and close tomaintain the level 36 of the hot water 38 in the hot water tank 22.Whenever the water level reaches the level of the lower level sensor 32,the controller 28 is alerted to actuate the solenoid-controlled tankfill valve 34 to open. When the tank fill valve opens, a suitablepressurized source of unheated water, such as from a utility watersource 36, is connected with the bottom of the hot water tank 22, andunheated water enters the bottom of the hot water tank 22. The entry ofthe unheated water into the bottom of the tank causes the level 36 torise, and when the level 36 reaches the level of the upper level sensor30, the controller 28 is alerted to remove power from the solenoid toclose the tank fill valve. In this way the level 36 is generally keptbetween the levels of the upper level sensor 30 and the lower levelsensor 32. The difference between the upper and lower levels may be assmall a couple of inches. Most importantly, the level 36 is kept above atop edge 38 the de-aerator 24 and the level of the tubular tank outletfitting 26.

The temperature of the hot water is maintained at a preselected hightemperature, i.e. near the boiling point, stored within the controllermemory. When a temperature sensor 40 indicates to the controller thatthe sensed temperature is less than the preselected high temperature,the controller 28 causes an electrical hot water heater 42 to becomeenergized to raise the temperature. When the sensed temperature is againraised above the preselected high temperature, the controllerdeenergizes the electrical hot water heater, and the temperature isallowed to again decrease either due to the removal of the hottest waterfrom the top or simply due to unavoidable thermodynamic loss out of thetop and sides of the tank, despite the tank 22 being insulated. In thisway the temperature of the hot water 38 in the tank 22 is kept atapproximately the preselected high temperature.

Communication with the controller a is preferably by means of a touchpaddisplay 42 which provides displays of information and virtual selectionkeys. The virtual, or soft, soft keys may be selected merely by a usertouching the screen at the location of the key. The microprocessor-basedcontroller 28 has a brew parameters memory in which is stored, inaddition to other operation data, a plurality of brew profiles fordifferent types of beverage and different varieties of the differenttypes, as well as for different batch sizes for the different profiles.Each profile includes the duration of total dispense period, theduration of any wetting period, steeping periods, batch size, durationof a drip period after the end of the dispense period. The profiles alsoinclude the duration of intermittent flow pulses of dispense water aswell as the number of such pulses and the duration of the gaps betweenflow pulses of dispense water, if intermittent dispensing is desired.Such pulse brew, or intermittent brew, operation, as well as furtherexplanation of profile parameters are shown in detail in U.S. Pat. No.6,448,717 issued to Zbigniew G. Lassota on Nov. 21, 2000 for aninvention entitled, “Beverage Maker with Intermittent Beverage LiquidDispenser and Apparatus and Method for Uniform Contact of BrewIngredient with Brew Water”, which is hereby incorporated by reference.

Unlike know brew cycle profiles, in accordance with the presentinvention the profiles of the present invention include specification ofthe precise level of the flow rete of dispense water into the brewbasket during each split second, such as one tenth second, thatdispensing occurs. In addition, the profile specifies gradual increasesand decreases of flow rate when the flow rate is transitioning between apreselected maximum flow rate and a zero-flow rate, in the split-secondincrements.

In keeping with one advantageous feature of the brewer 20 of the presentinvention, unlike some known brewers in which a solenoid controlleddispense valve, or brew valve, can only be fully open or fully closed,and average flow rate can only be lowered by employing pulse brewing asnoted above, in the present invention an electrical pump 44 replaces thecommonly used solenoid controlled solenoid.

More importantly, the electrical pump 44 is a type of pump that iscapable of having its flow rate selectively varied in accordance with afinely designed profile with a sub-second resolution without resortingto pulse brew operation, if not desired. For example, the flow rate maysimply vary between one relatively low but non-zero flow rate and arelatively higher and non-zero flow rate, without ever a pause duringwhich there is zero flow rate. Such control is not possible with an openor close valve.

If used with pulse brew operation, on the other hand, and much greaterlevel of control is achievable. The use of a finely controlled pump 44enables pulse brew operation with alternating periods of flow andnon-flow with periods of flow at different magnitudes, or flow rates,from one brew cycle to the next or during a single dispense period of asingle brew cycle. Also, as noted, a type of pulse brew can be providedin which the flow rate is never zero but fluctuates in pulse like mannerbetween low and high flow rates which may also vary during a singledispense period. As will be explained in greater detail below, thisability to finely control the flow rate of hot water being provided to adistribution head enables selective changes to the spray pattern of hotwater impinging upon the top surface of the beverage ingredient withinthe brew basket.

The inventors have determined that repeatability of the actual desiredflow profile as measured during repetitive brew cycles using the sameprofile is enhanced by ensuring that the electric pump flow rate isindependent of hot water head level fluctuations within the hot watertank 22. This is achieved by mounting the hot water outlet 26 adjacentthe but slightly beneath the lowest level of water in the hot water tanknear the top of the hot water tank 22. The variation in head pressure isthen no greater than the difference between the highest level and thelowest level, which may be separated by as little as two inches. Theoutlet fitting is connected to an input port of the pump 44 by means ofa flexible tube 46.

Moreover, enhanced control resolution is achieved by use of a powersupply 45 for the pump 44 that generates a duty cycle modulated, squarewave, DC power voltage at a frequency of approximately three hundredHertz. This DC power voltage is a square wave DC signal of fixedamplitude, such as twelve volts DC, but with a duty cycle that may beselectively varied, as shown in FIG. 3 , with a digital control signalfrom the controller 28 to selectively, and finely change the duty cycleand thus the average output voltage.

Preferably, the pump 44 is a sealed, brushless, centrifugal,impeller-type DC pump 44 equipped to pump near boiling hot water. thepump which operates with a flow rate that that is controllable betweenzero flow rate and a maximum flow rate of not less than 1.5 L/min. byvarying the DC power voltage between approximately six volts DC andtwelve volts DC. Importantly, the pump is capable of very fine flow ratecontrol through control of the duty cycle of the pulsed, DC powervoltage provided to the pump 44 to modulate the flow rate multiple timesat a sub-60 Hz rate, such as approximately 300 Hz.

Lowering the duty cycle of the pulsed DC power voltage over a periodwith a number of pulses lowers the average DC voltage during thatperiod. On the other hand, increasing the duty cycle of the pulsed. DCpower voltage over a period with number of pulses raises the average DCvoltage during the period of increased duty cycle. The duty cycle may beincreased or decreased gradually or rapidly to gradually or rapidlyincrease or decrease the average DC power voltage being supplied to thepump. Each different average DC power voltage level is associated with acorresponding flow rate of the electrical pump between zero and any flowrate greater than zero and less than the maximum

An inlet connector 46 of the pump is directly connected with the opentank outlet connector 26 by means of a tubular connector, and an outlet48 of the pump is directly connected to a spray distribution head 50,via a fully open flexible tube 52. Importantly, the tank outletconnector 26 is located beneath the preselected lower level limitassociated with the lower level sensor, and is thus always beneath thelevel 36 of the hot water 38, as is the pump 44. Accordingly, the pumpinlet 46 is always flooded with hot water even when the pump 44 is notpumping.

Accordingly, the pump 44 in this preferred configuration is referred toas a “flooded suction pump”. Because of the flooded suction the amountof power required to move a given amount of water is reduced compared toother configurations and the presence of air in the pumped water 38 isreduced. Further reducing the presence of air in the hot water beingpumped is the de-aerator 24, noted above. The de-aerator 24 is definedby a box with an open top but closed bottom and side walls thatterminate at a sharp top edge 39 of the open top. The outer wall of thede-aerator 24 may comprise a section of the outer wall of the tank 22,although a separate outer wall could be provided. The tank outletconnector 26 is connected to this wall section at a level beneath thesharp top edge 39 of the de-aerator. Thus, all the hot water 38 ispumped from out of the interior of the box defined by the de-aerator 24.As the water is pumped from the box, water from outside of the box butwithin the hot water tank 22 flows over the top sharp edge 39 and intothe interior of the box. As the water 38 flows over the sharp top edge39, air bubbles in the water are scraped, broken or otherwise penetratedby the sharp edge 39 and released to atmosphere.

Accordingly, air bubbles are advantageously excluded from the waterentering an inlet 46 of the pump 44 flow through the pump 44 to preventcavitations. If the air bubbles are not excluded, they will displace thewater in the outflow and thereby reduce the actual outlet flow rate ofthe water for a given pump speed. In such case, the actual flow rate ofthe water for a given pump speed varies depending upon how much air isin the flow. The water flow rate this becomes indeterminate.Accordingly, the flow rate far the same profile may result in differentactual flow rates depending upon the amount of air bubbles present. Insuch case, actual flow rate of the water alone cannot be reliablyreproduced, or repeated, from one brew cycle to the next even though thebrew profile and corresponding pump input voltage profile remains thesame.

The water from the spray head 50 is dispensed into a brew basketassembly 52 to percolate through beverage ingredient 53 supported on afilter paper supported by a wire mesh, or otherwise water permeable,filter holder 54. The filter holder has a gap 56 between an outer brewbasket body 58 at the top of the brew basket body 58 through whichbypass water may be allowed to pass by the beverage ingredient withinthe filter holder 54 and but down the interior sides of the brew basket52 and out the brew basket drain hole. After mixing with the ingredientto form the desired beverage, the beverage passes out of the brew basketassembly 52 and into a suitable container, such as an insulateddispenser 60 with a dispense faucet 62 for serving the beverage.

The flow rate may be continuous throughout the dispense period duringwhich time the level of the flow rate may be selectively changed betweennear zero and the maximum flow rate. For example, the flow rate may beat a relatively low level at the beginning of a dispense period, at anintermediate level during the middle portion and then at a maximum levelat the end of the dispense cycle. Any pattern of variations in flow rateduring the dispense period may be stored in the controller 28 and thenselected by an operator for a particular type or variety of beverageingredient. By increasing or decreasing the average flow rate whilekeeping the dispense period constant, the batch quantity may beincreased or decreased, respectively. Alternatively, the batch quantitymay be kept constant, even though the dispense time period is increasedor decreased, by respectively proportionately decreasing or increasingthe average flow rate.

In the case of pulse brew operation, the high degree of control providedby the pump 44 with duty cycle control being used in lieu of a solenoidcontrolled dispense valve, or dump valve (as described in U.S. Pat. No.6,148,717 issued Nov. 21, 2000 for an invention entitled “Beverage Makerwith Intermittent Beverage Liquid Dispenser and Method for UniformContact of Brew Ingredient with Brew”), the degree of control over flowrates, batch size and dispense period duration is further enhanced. Insuch case, the dispense profile provides for intermittent rather thancontinuous dispensing during the dispense period, such as shown in FIG.2 , there are periods, each of approximately ten seconds duration,during which dispense water is passed to the brew basket, as indicatedby pulses 64 and 66 separated by periods of no flow, also each ofapproximately ten seconds in duration, such as periods 68, 70, 72 and74, during which there is no flow.

Unlike a solenoid controlled valve which is either fully closed with afixed maximum flow rate dependent upon the head level of the water inthe hot water tank, or is fully closed with no flow, with the beveragebrewer 20 of present invention it is possible selectively change themaximum flow rate of each of the pulses of high flow rate, if desired,and to also, if desired, to provide for a relatively lower but non-zeroflow rate between pulse of relatively low flow rate.

As illustrated by the continuous increasing ramp 76, during the start ofa pulse of flow, the average voltage applied to the pump 44 ispreferably increased gradually to reduce wear and tear on the motor 44due to rapid and large increases from zero or other relatively lowvoltage to a maximum or relatively higher voltage. Alternatively, thepower input voltage is gradually increased with a stepped increasingramp 78 with three or more small jumps in voltage. For similar reasons,abrupt stops of the pump are prevented by providing either a continuousdecreasing DC power voltage ramp 80 or a stepped decreasing ramp 82 atthe end of a relatively period of relatively high input DC powervoltage.

Referring to FIG. 3 , the flow rate of the pump 44 varies directly withthe pulse width, or duty cycle, of the DC power voltage that is providedto the pump 44. When the pulse width and duty cycle of each of a seriesof DC power voltage pulses generated by the duty cycle modulated DCpower supply 45 is relatively low over a period of time, such as pulse78, the series of such pulses provides a relatively low average DCvoltage over that period of time. For instance, if the duty cycle isfifty percent, and the fixed maximum voltage level Vo is twelve voltsDC, the average DC voltage over a plurality of cycles will be fiftypercent of twelve volts, or six volts. Series of pulses of greaterwidth, such as pulses 80, 82, and 84, with greater duty cycles willprovide larger average voltages proportional to the duty cycle.Depending upon the electromechanical characteristics of the pump, aminimum duty cycle of greater than zero may result in zero flow of thepump while a maximum flow rate will always generally result from pulseshaving a one hundred percent duty cycle. The exact relationship of dutycycle percentage and corresponding flow rate between zero duty cycle andone hundred percent duty cycle is not necessarily linear and should bedetermined empirically.

In addition to being capable of precise control of flow rates anddispense times, it is possible during the dispense time period toselectively control the flow rate to achieve different spray patternsonto the beverage ingredient within the brew basket. This is preferablyachieved though use of a spray distribution head assembly 85, such asshown in FIG. 4 . Reference should be made to U.S. Pat. No. 7,866,255issued to Wroblewski, hereby incorporated by reference, for a detaileddescription of the spray distribution head assembly 85, which is herebyincorporated by reference. Briefly, the distribution head has an inletcover with a vertical inlet coupler 86 connected through a flexible tube88. Dispense water from the tube 88 passes through a vertical passageway90 onto the peak 94 of an umbrella-like distribution plate 92. The waterpasses from the peak 94 though closed channels into open, upwardlyfacing, water distribution channels 98 and 100 formed in the top of thedistribution plate distribution plate 92. Because the channels are open,very little back pressure is built up and the spray distribution patterncan be substantially affected by the flow rate of water entering theinlet coupler. While the spray distribution head assembly 85 ispreferred, it should be appreciated that there may be other types ofspray distribution heads with flow rate dependent spray distributionpatterns.

The selected average flow rate is one-half to one-and-one-half gallonsper minute for producing either one-half gallon or three liters ofbeverage during a single brew cycle. When producing a batch of threegallons during a brew cycle, instead of only one one-half gallon, theaverage flow rate is increased proportionately to approximately two tothree-and-one-half gallons per minute. It should be appreciated thatwith pumps of different capacities different flow rates may beobtainable.

In accordance with the present invention, the variation in flow rate ofdispense water is used to selectively change the distribution spraypatterns of water onto the top surface of the beverage ingredient 53within the brew basket assembly 52. Referring to FIGS. 5A and 5B, whenthe flow rate is relatively low, such as approximately one-half, thespray distribution pattern 102 is generally vertical. Referring to FIGS.6A and 6B, when the flow rate is relatively greater, such as one to oneand one-half gallons/minute, then the spray distribution pattern 104 hasa component that extends radially outwardly from the vertical at anacute angle.

Achieving another object of the invention, the need for a separatebypass valve or motor may be eliminated by provision of a brew basketassembly 52 like that of FIG. 7 . Brew basket assembly 52 has one ormore upwardly facing bypass gaps 56 between the brew basket outerhousing 58 and the filter holder 54 The bypass gaps 56 are present atthe upwardly facing top of the brew basket outer housing 58 or receiptof dispense water from the spray distribution head 85. In such case,referring to FIGS. 8A and 8B, when the flow rate is increased to twogallons per minute to two-and-one-half gallons per minute, then thespray distribution pattern has a component that extends radiallyoutwardly by a sufficient amount to be received against the insidesurface of the outer brew basket body 58 and into the bypass gap 55.Once passing through the bypass gap 56, the water moves past theingredient and directly into the dispenser 60.

Referring now to FIGS. 9-11 , a detailed perspective explodedillustration of a preferred embodiment is shown together with theconnection with the pump 44 and spray distribution head 50. In addition,in this embodiment, an optional second pump, or bypass pump 110 isprovided solely for pumping a selected amount of bypass water into thebypass gap 56. As seen in FIG. 9 , the hot water tank 22 has a siliconY-connector 112 for connecting both primary pump 44 and bypass pump 110to a brew water fitting 114. The bypass pump 110 is connected via a leg113 of the Y-connector 112. Mother fitting may also be provided on theside of the hot water tank 22 for connection to a hot water faucet. Tankvents 116 and 118 are provided at the top the tank 22 above thede-aerator 24 to vent the tank to atmosphere. A pump tube adapter 86converts a standard solenoid operated spray distribution system into apump operated version of the present invention. The spray dome 92 isremovable from the upper connection with the core beneath the uppercover 85 of the distribution system.

While a particular embodiment has been shown in detail, it should beappreciated that many obvious variations and alterations may be madewithout departing from the spirit of the invention and the scope of theappended claims.

The invention claimed is:
 1. For use in an electrical beverage brewerwith a brew basket for holding beverage ingredient for brewing abeverage, an unpressurized hot water tank, a water fill system formaintaining water level in the tank between preselected limits, a methodof brewing, comprising the steps of: dispensing hot water from theunpressurized hot water tank, while the hot water tank is connected toatmosphere, with a variable speed pump, onto a spray distribution domewith an upper surface for receiving hot water from the pump, said domehaving upwardly facing, open, surface channels to direct the hot waterfrom the pump into individual streams of hot water deposited into thebrew basket; and controlling with an electronic controller a variableelectrical power supply connected to the pump to selectively change theapplication of electrical power to the variable speed pump toselectively vary the flow rate of hot water passing out of the pump andonto the spray distribution dome during a preselected dispense period ofa brew cycle; and creating with said spray distribution domesubstantially different spray patterns in response to receiving hotwater at different preselected flow rates of the pump.
 2. The brewingmethod of claim 1 in which the pump is a variable speed, flooded suctionpump with an inlet located beneath a lowest one of the preselected waterlevel limits, and an outlet above a highest one of e preselected waterlevel limits.
 3. The brewing method of claim 1 in which the pump has animpeller speed with a corresponding flow rate that varies directly withthe electrical power provided to the pump by the variable power supply,and including the step of varying the electrical power provided to thepump to change e flow rate.
 4. The method of claim 1 in which the brewbasket has an outer water impervious protective body with an outer topedge and an inner water pervious filter holder with an upper perimeterspaced from the outer top edge to provide a gap for the passage ofbypass water, and including the step of operating the pump at a flowrate sufficiently high to cause at least some of the streams of water toflow downwardly and outwardly from the dome at an acute angle and passthrough the bypass water gap and miss the filter holder.
 5. The brewingmethod of claim 1 in which the pump is a sealed, brushless, centrifugalimpeller type pump suitable for pumping boiling hot water.
 6. Thebrewing method of claim 1 in which the pump has an impeller speed with acorresponding flow rate that varies directly with the average electricalDC power voltage provided to the pump by the variable power supply. 7.The brewing method of claim 1 in which the controller has a storedprogram with a dispense profile to cause the duty cycle to graduallydecrease when the DC power voltage is decreased from a higher voltage toa substantially lower voltage during at least a part of a dispenseperiod.
 8. The brewing method of claim 1 in which the controller has astored program with a dispense profile to cause a plurality ofintermittent alternate periods of pumping when the duty cycle is at onelevel and non-pumping when the duty cycle is at another level lower thanthe one level during at least part of a dispense period.
 9. The brewingmethod of claim 1 in which the controller has a stored program with adispense profile, and including the step of using the stored dispenseprofile to cause a plurality of intermittent alternate periods when theduty cycle is at a preselected non-zero value associated with a periodof pumping and when the duty cycle is at another value less than thepreselected non-zero value associated with a period of non-pumping,cause the duty cycle to gradually increase from the other value to thepreselected non-zero value to gradually begin a period of pumping, andcause the duty cycle to gradually decrease from the preselected nonzerovalue to the other value gradually stop a period pumping.
 10. For use inan electrical beverage brewer with a brew basket for holding beverageingredient for brewing a beverage, an unpressurized hot water tank, awater fill system for maintaining water level in the tank betweenpreselected limits, a method of brewing, comprising the steps of:dispensing hot water from the hot water tank with a variable speed pumponto a spray distribution dome with an upper surface for receiving hotwater from the pump, said dome having upwardly facing, open, surfacechannels to direct the hot water from the pump into individual streamsof hot water deposited into the brew basket; and controlling with anelectronic controller a variable electrical power supply connected tothe pump to selectively change the application of electrical power tothe variable speed pump to selectively vary the flow rate of hot waterpassing out of the pump and onto the spray distribution dome during apreselected dispense period of a brew cycle; creating with said spraydistribution dome substantially different spray patterns in response toreceiving hot water at different preselected flow rates of the pump;producing a variable DC power voltage with the variable electrical powersupply having a square wave configuration with a duty cycle that isselectively varied to selectively change the average DC power beingproduced by the variable electrical power supply; storing a program inthe controller with a dispense profile that includes at least one periodduring which a first duty cycle is selected for a relatively low pumpflow rate to cause the streams of water to flow downward from the domeinto the brew basket in a relatively vertical direction, and at leastone other period during which a second duty cycle greater than the firstduty cycle is selected for a relatively high flow rate to cause thestreams of water to flow downwardly and outwardly from the dome at anacute angle relative to vertical.
 11. For use in an electrical beveragebrewer with a brew basket for holding beverage ingredient for brewing abeverage, an unpressurized hot water tank, a water fill system formaintaining water level in the tank between preselected limits, a methodof brewing, comprising the steps of: dispensing hot water from the hotwater tank with a variable speed pump onto a spray distribution domewith an upper surface for receiving hot water from the pump, said domehaving upwardly facing, open, surface channels to direct the hot waterfrom the pump into individual streams of hot water deposited into thebrew basket; and controlling with an electronic controller a variableelectrical power supply connected to the pump to selectively change theapplication of electrical power to the variable speed pump toselectively vary the flow rate of hot water passing out of the pump andonto the spray distribution dome during a preselected dispense period ofa brew cycle; and creating with said spray distribution domesubstantially different spray patterns in response to receiving hotwater at different preselected flow rates of the pump and in which thecontroller has a plurality of brew dispense profiles stored in memory,and including the step of producing with the variable electrical powersupply a variable DC power voltage with a square wave DC output voltagehaving a duty cycle that is selectively varied in accordance with theprofiles to selectively change the average DC power being provided tothe variable speed pump during a dispense period.
 12. The brewing methodof 11 in which the frequency of the DC output voltage square wave has asub-second period to enable sub-second adjustments to the flow rate ofthe variable speed pump.
 13. The brewing method of claim 12 in which thevariable speed pump has a recommended, maximum operating, average inputpower voltage, and the power supply produces the recommended, maximumoperating, average input power voltage when operated to produce anoutput power voltage square wave with a duty cycle of approximately onehundred percent.
 14. For use in an electrical beverage brewer with abrew basket for holding beverage ingredient for brewing a beverage, anunpressurized hot water tank, a water fill system for maintaining waterlevel in the tank between preselected limits, a method of brewing,comprising the steps of: dispensing hot water from the hot water tankwith a variable speed pump onto a spray distribution dome with an uppersurface for receiving hot water from the pump, said dome having upwardlyfacing, open, surface channels to direct the hot water from the pumpinto individual streams of hot water deposited into the brew basket; andcontrolling with an electronic controller a variable electrical powersupply connected to the pump to selectively change the application ofelectrical power to the variable speed pump to selectively vary the flowrate of hot water passing out of the pump and onto the spraydistribution dome during a preselected dispense period of a brew cycle;and creating with said spray distribution dome substantially differentspray patterns in response to receiving hot water at differentpreselected flow rates of the pump and in which the variable powersupply produces a square wave output voltage with a frequency ofapproximately 300 Hz.
 15. For use in an electrical beverage brewer witha brew basket for holding beverage ingredient for brewing a beverage, anunpressurized hot water tank, a water fill system for maintaining waterlevel in the tank between preselected limits, a method of brewing,comprising the steps of: dispensing hot water from the hot water tankwith a variable speed pump onto a spray distribution dome with an uppersurface for receiving hot water from the pump, said dome having upwardlyfacing, open, surface channels to direct the hot water from the pumpinto individual streams of hot water deposited into the brew basket; andcontrolling with an electronic controller a variable electrical powersupply connected to the pump to selectively change the application ofelectrical power to the variable speed pump to selectively vary the flowrate of hot water passing out of the pump and onto the spraydistribution dome during a preselected dispense period of a brew cycle;and creating with said spray distribution dome substantially differentspray patterns in response to receiving hot water at differentpreselected flow rates of the pump, and in which the controller has astored program with a dispense profile to cause the duty cycle togradually increase to increase the average DC power voltage from a lowervoltage to a substantially higher voltage during at least a part of adispense period.
 16. For use in an electrical beverage brewer with abrew basket for holding beverage ingredient for brewing a beverage, anunpressurized hot water tank, a water fill system for maintaining waterlevel in the tank between preselected limits, a method of brewing,comprising the steps of: dispensing hot water from the hot water tankwith a variable speed pump onto a spray distribution dome with an uppersurface for receiving hot water from the pump, said dome having upwardlyfacing, open, surface channels to direct the hot water from the pumpinto individual streams of hot water deposited into the brew basket;controlling with an electronic controller a variable electrical powersupply connected to the pump to selectively change the application ofelectrical power to the variable speed pump to selectively vary the flowrate of hot water passing out of the pump and onto the spraydistribution dome during a preselected dispense period of a brew cycle;creating with said spray distribution dome substantially different spraypatterns in response to receiving hot water at different preselectedflow rates of the pump; producing with the variable power supply avariable DC power voltage with a square wave having a duty cycle that isselectively varied to change the average DC power being produced by thevariable electrical power supply; and storing a program in thecontroller with a dispense profile that includes at least one periodduring which a first duty cycle is selected for a relatively low pumpflow rate to cause the streams of water to flow downward from the domeinto the brew basket in a relatively vertical direction, and at leastone other period during which a second duty cycle greater than the firstduty cycle is selected for a relatively high flow rate to cause thestreams of water to flow downwardly and outwardly from the dome at anacute angle relative to vertical.
 17. The brewing method of claim 16including the steps of providing the brew basket with an inner waterpervious filter holder with an upper perimeter spaced from the outer topedge to provide a bypass gap for the passage of bypass water, andproviding a relatively high flow rate causing at least some of thestreams of water to flow downwardly and outwardly from the dome at anacute angle and pass through the bypass water gap and miss the filterholder.
 18. For use in an electrical beverage brewer, a method ofbrewing, comprising the steps of: maintaining water level in a hot watertank between preselected limits located sufficiently close together tomaintain a substantially uniform head pressure in the hot water tank;holding ingredient to be brewed upon mixing with hot water in a brewbasket; dispensing water into the brew basket with a water dispensesystem by pumping hot water out of the hot water tank with a variablespeed electrical pump, and selectively varying with a power controllingmeans an amount of non-zero electrical power to the pump to selectivelyvary a non-zero speed of the pump and resultant flow rate of hot waterout of the pump, said power controlling means selectively changing a DCpower voltage greater than zero provided to the pump to selectively varya non-zero speed of the pump and resultant non-zero flow rate duringoperation of the pump.
 19. The brewing method of claim 18 including thesteps of directing hot water from the pump, with a dome shapedconfiguration a spray distribution head, into individual streams of hotwater that enter the brew basket in a vertical direction, andselectively varying non-vertical directions depending upon the flaw rateof the pump.
 20. The brewing method of claim 18 including the steps ofproviding the brew basket with an inner water pervious filter holderwith an upper perimeter spaced from the outer top edge to provide abypass gap for the passage of bypass water, and providing a relativelyhigh flow rate causing at least some of the streams of water to flowdownwardly and outwardly from the dome at an acute angle and passthrough the bypass water gap and miss the filter holder.